U.S. Pat. Nos. 4,032,517 and 4,092,302 are directed to fiber-forming polyamides containing phosphorus wherein the phosphorus is present as radicals of the formula: ##STR1## wherein Z is an alkyl radical having 1-4 carbon atoms and r and s are individually the integers 2 or 3. Fibers produced from these polyamides are disclosed as exhibiting permanent antistatic, moisture transport and flame-resistant properties. The only compounds specifically disclosed and exemplified in the above patent, however, are the methyl and ethyl derivatives, i.e. those derivatives wherein Z is methyl or ethyl.